> Black holes are wrapped in event horizons.

Not really - the event horizon is the effect of the black hole, not something separate from it. Also, from one perspective there is nothing mysterious about it - an observer passing through it would not notice any kind of border there (though an observer who is not passing through it would see it as some kind of barrier emitting Hawking radiation).

Also note that physicists do not believe that there is any infinity at the center of a black hole. With a theory of quantum gravity we may even be able to describe the structure of the core of a black hole (though it would remain forever an un-testable model). Just like classical mechanics allows a particle to gain unbounded speed, GR allows a mass to gain unbounded gravity, but that is likely incorrect, we just don't know how to describe the limit yet.

> The digits of pi would require all the energy of the universe to calculate.

This makes no sense - pi has an infinite number of digits, so all of the energy in the universe can't possibly be enough to compute it.

> Calculating the brain with sufficient accuracy (using our current computational framework) would require a computer so large it would generate a black hole...

I find this hard to believe. Regardless, there is no infinity in the human brain.

Note that in general infinity is an inherently non-scientific concept - there is no way to experimentally distinguish an infinity from a quantity larger than the largest possible experiment.

> Also note that physicists do not believe that there is any infinity at the center of a black hole.

This is my impression as well, but do you have a good source for it? If I'm talking with people about black holes, it would be nice to have something to point to besides my vague impression from watching physics lectures.

This blog post from a theoretical physicist should be a decent source:

http://backreaction.blogspot.com/2020/05/a-brief-history-of-...

Any physics equations have limits of applicability. If a singularity appears in the solution to the equations, that is a sign that you have found one of these limits, not that there is an actual infinity there.

>pi has an infinite number of digits, so all of the energy in the universe can't possibly be enough to compute it.

If the universe is also infinite, then you could calculate Pi with X% of the universe's energy, where X is an arbitrarily small positive number.

If the universe is infinite, you could compute all of the digits of Pi in finite time by using an infinite amount of parallel computers, true. But computing a percentage of an infinite number (total energy in the universe) doesn't make sense.

Just calculate digits of pi in base pi, it's 1.0 exactly.

Then calculate the digits of the area of a square in base pi :)